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为了研究玄武岩纤维混凝土(Basalt fiber reinforced concrete,简称BFRC)在冲击荷载下的增韧性能,通过直径为74 mm的分离式霍普金森压杆(Split Hopkinson Pressure Bar,简称SHPB)试验装置得到BFRC冲击压缩全过程的动态应力-应变曲线,对纤维体积含量分别为0%、0.05%、0.1%、0.15%、0.2%、0.25%的玄武岩纤维增强混凝土进行不同应变率下的冲击试验研究,主要考察了平均应变率和纤维掺量对混凝土韧性的影响.同时利用扫描电镜(SEM)对纤维与混凝土的界面进行观察,探求纤维对混凝土的增韧机理.研究表明,BFRC的韧性存在明显的应变率强化效应,材料的峰值韧性和极限韧性与应变率呈近似的线性增长关系,应变率和纤维掺量是影响韧性的关键因素,不同强度等级的混凝土存在与其相对应的最佳纤维掺量.
In order to study the toughening behavior of basalt fiber reinforced concrete (BFRC) under impact load, BFRC shock was obtained by a split Hopkinson Pressure Bar (SHPB) test device with a diameter of 74 mm The dynamic stress-strain curve of the whole process of compression tests was carried out. The impact tests of basalt fiber reinforced concrete with different fiber volume fractions of 0%, 0.05%, 0.1%, 0.15%, 0.2% and 0.25% The effects of average strain rate and fiber content on the toughness of concrete were also investigated.Finally, the interface between fiber and concrete was observed by scanning electron microscope (SEM), and the toughening mechanism of fiber to concrete was explored.The results show that there is obvious strain rate The strengthening effect shows that the peak toughness, the ultimate toughness and the strain rate of the material exhibit an approximately linear growth relationship. The strain rate and the fiber content are the key factors affecting the toughness. The optimal fiber content of concrete with different strength grades exists.